Question: Simplify the following expression: $t = \dfrac{7r}{5} - \dfrac{r}{6}$
In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $5$ and $6$ $\lcm(5, 6) = 30$ $ t = \dfrac{6}{6} \cdot \dfrac{7r}{5} - \dfrac{5}{5} \cdot \dfrac{r}{6} $ $t = \dfrac{42r}{30} - \dfrac{5r}{30}$ $t = \dfrac{42r -5r}{30}$ $t = \dfrac{37r}{30}$